On 11/09/2024 12:24, Ayan Kumar Halder wrote:
On 11/09/2024 10:55, Julien Grall wrote:
Hi,
Hi,
On 11/09/2024 10:44, Ayan Kumar Halder wrote:
From: Michal Orzel <michal.or...@amd.com>
AoU are the assumptions Xen relies on other components (eg platform,
domains)
to fulfill its requirements. In our case, platform means a
combination of
hardware, firmware and bootloader.
We have defined AoU in the intro.rst and added AoU for the generic
timer.
Signed-off-by: Michal Orzel <michal.or...@amd.com>
Signed-off-by: Ayan Kumar Halder <ayan.kumar.hal...@amd.com>
---
Changes from :-
v1 - 1. Removed the part of requirement which states that Xen exposes
the
frequency of the system timer by reading the "clock-frequency" property.
2. Added a rationale for AoU.
3. Reworded the AoU.
.../reqs/design-reqs/arm64/generic-timer.rst | 24 ++++++++++++++++++-
docs/fusa/reqs/intro.rst | 10 ++++++++
2 files changed, 33 insertions(+), 1 deletion(-)
diff --git a/docs/fusa/reqs/design-reqs/arm64/generic-timer.rst b/
docs/fusa/reqs/design-reqs/arm64/generic-timer.rst
index f2a0cd7fb8..86d84a3c40 100644
--- a/docs/fusa/reqs/design-reqs/arm64/generic-timer.rst
+++ b/docs/fusa/reqs/design-reqs/arm64/generic-timer.rst
@@ -30,7 +30,7 @@ Read system counter frequency
Description:
Xen shall expose the frequency of the system counter to the domains in
-CNTFRQ_EL0 register and/or domain device tree's "clock-frequency"
property.
+CNTFRQ_EL0 register.
This either wants to be split or explained in the commit message.
Yes, I will explain this in the commit message. Does the following sound
fine ?
```
docs: fusa: Add Assumption of Use (AoU)
AoU are the assumptions that Xen relies on other components (eg
platform, domains)
to fulfill its requirements. In our case, platform means a combination of
hardware, firmware and bootloader.
We have defined AoU in the intro.rst and added AoU for the generic timer.
Also, fixed a requirement to denote that Xen shall **not** expose the
system counter frequency via the "clock-frequency" device tree property.
The reason being the device tree documentation strongly discourages the
use of this peoperty. Further if the "clock-frequency" is exposed, then
it overrides the value programmed in the CNTFRQ_EL0 register.
So, the frequency shall be exposed via the CNTFRQ_EL0 register only and
consequently there is an assumption on the platform to program the
register correctly.
```
LGTM
Reviewed-by: Julien Grall <jgr...@amazon.com>
Cheers,
--
Julien Grall
